Resected cytokeratin-negative small cell lung carcinoma. BMJ Case Rep 2023 Apr 03;16(4)
Date
04/04/2023Pubmed ID
37011997Pubmed Central ID
PMC10083812DOI
10.1136/bcr-2022-253918Scopus ID
2-s2.0-85151707665 (requires institutional sign-in at Scopus site)Abstract
Small cell lung carcinoma (SCLC), a malignancy of neuroendocrine origin, can show varied morphologies and patterns but is typically positive for at least one neuroendocrine marker and almost always for cytokeratins. It is essential to distinguish this tumour due to its characteristic genetic features, aggressive behaviour, propensity for metastasis and responsiveness to chemotherapy. We hereby present a rare case of a pulmonary mass that showed morphological features of an SCLC but lacked cytokeratin expression on biopsy as well as resection specimens. Various cytokeratins were tested on multiple blocks and at different laboratories. A broad differential diagnosis was considered and ruled out including small round blue cell tumours, non-SCLC and metastasis. After performing an extensive work-up to identify the origin of this tumour, it was finally diagnosed as SCLC with expression of neuroendocrine markers synaptophysin and CD56, and intracytoplasmic electron dense neurosecretory granules (250-350 nm) however lacked cytokeratin expression.
Author List
Jain PV, Thompson J, Sheinin YAuthors
Yuri M. Sheinin MD, PhD Associate Professor in the Pathology department at Medical College of WisconsinJonathan R. Thompson MD Assistant Professor in the Medicine department at Medical College of Wisconsin
MESH terms used to index this publication - Major topics in bold
Biomarkers, TumorBiopsy
Carcinoma, Neuroendocrine
Carcinoma, Non-Small-Cell Lung
Humans
Keratins
Lung Neoplasms
Small Cell Lung Carcinoma
